Applied Genetic and Epigenetic Influences on High and Low Immune Responder Phenotypes of Dairy Cattle

免疫系统旨在控制传染病，因此，与低应答者相比，高免疫应答者将具有健康优势是合理的。具有增强的免疫反应（IR）的食用动物应具有降低的疾病风险，需要较少的治疗干预，包括抗生素，从而生产出质量更好的牛奶和肉类。圭尔夫大学先前的研究现在允许奶牛和小牛使用专利测试系统被分类为高、中或低免疫应答者。为了提供针对不同病原体的保护，获得性免疫包括两个组分，抗体（AMIR）和细胞介导的免疫应答（CMIR）。对2个研究牛群和一组商业牛群的研究表明，高反应者的疾病风险较低。AMIR和CMIR的遗传力均在0.25左右，说明通过遗传选择改良这些性状是可行的。正在进行的研究重点是了解更多关于影响这些独特而重要的表型的分子，基因和DNA结构差异（表观遗传效应）。此外，还有很多关于应用的知识需要学习。

The immune system is designed to control infectious disease and it is therefore reasonable to expect that high immune responders will have health advantages compared to low responders. Food-producing animals with enhanced immune responses (IR) should have reduced risk of disease, require less therapeutic intervention, including antibiotics, thereby producing milk and meat of improved quality. Previous research at the University of Guelph now allows dairy cows and calves to be classified as high, average or low immune responders using a patented test system. In order to provide protection against diverse pathogens, adaptive immunity includes two components, antibody (AMIR) and cell-mediated immune responses (CMIR). Studies in 2 research herds and a set of commercial herds show that high responders have lower risk of disease. Heritability of AMIR and CMIR are ~ 0.25 indicating that it is possible to improve these traits via genetic selection. Ongoing research is focused on learning more about the molecules, genes and DNA structural differences (epigenetic effects) that influence these unique and important phenotypes. Additionally, there is great deal more to learn about applying